On TV, I require movie breaks to stretch my legs, snatch water and food and go to the loo. Especially if it's a REALLY LONG MOVIE. I can't remember what channel it is, but whichever channel has their movies sponsored by Stella Artois always has perfect breaks for me.

What is damn annoying is when a half-hour show winds up being about fifteen minutes due to adverts. GRAWR.

On-topic: That's never really annoyed me. It gives me time to zone out and be pensive, just as the credits do. And they normally expand again after a bit.